Dirichet空间上Toeplitz算子的若干问题

讨论了Dirichlet空间上Toeplitz算子的紧性,特别地得到了Schatlen类Toeplitz算子的特征.此外,还证明了关于Toeplitz算子的一个非稠密性定理,并证明一个非零的函数可以诱导一个零算子,这与Hardy空间及Bergman空间情形是一重大差别.     

Toeplitz Operators on Dirichlet Spaces

In this paper we study Toeplitz operators on Dirichlet spaces and describe the boundedness and compactness of Toeplitz operators on Dirichlet spaces. Meanwhile, we give density theorems for Toeplitz operators on Dirichlet spaces Received December 22,1998, Revised March 27, 2000, Accepted June 27, 2000     

Dirichlet空间上的Toeplitz算子

本文研究了Dirichlet空间上的Toeplitz算子,部分的回答了文[1]中的问题,给出了关于Dirichlet空间上Toeplitz算子的一个稠密性定理。     

Dirichlet空间上Toeplitz算子的紧性

本文给出了 Ｄｉｒｉｃｈｌｅｔ空间上 Ｔｏｅｌｐｉｔｚ算子为紧算子的充要条件,并证明具有 Ｃ１－符号的 Ｔｏｅｐｌｉｔｚ算子为紧算子当且仅当它为零算子,当且仅当符号的边值为零．     

Dirchlet空间上ToePlitz算子的紧性

本文给出了Dirichlet空间上Toelpitz算子为紧算子的充要条件.并证明具有C     

Toeplitz Operators on Generalized Bergman Spaces

We consider the weighted Bergman spaces HL²(\mathbb B^d, m_l){\mathcal {H}L^{2}(\mathbb {B}^{d}, \mu_{\lambda})}, where we set dm_l(z) = c_l(1-|z|²)^l dt(z){d\mu_{\lambda}(z) = c_{\lambda}(1-|z|^2)^{\lambda} d\tau(z)}, with τ being the hyperbolic volume measure. These spaces are nonzero if and only if λ > d. For 0 < λ ≤ d, spaces with the same formula for the reproducing kernel can be defined using a Sobolev-type norm. We define Toeplitz operators on these generalized Bergman spaces and investigate their properties. Specifically, we describe classes of symbols for which the corresponding Toeplitz operators can be defined as bounded operators or as a Hilbert–Schmidt operators on the generalized Bergman spaces.     

Toeplitz Operators on Analytic Besov Spaces

We characterize complex measures μ on the unit disk for which the Toeplitz operator T _μ is bounded or compact on the analytic Besov spaces B _p with 1 ≤ p < ∞. Research supported in part by NSF grant, DMS 0200587 (first author); and by a NSERC grant (third author).     

On Toeplitz Operators Between Fock Spaces

We study some mapping properties of Toeplitz operators T _μ associated with nonnegative Borel measures μ on the complex space ${\mathbb{C}^n}$ . In particular, we describe the bounded and compact properties of T _μ acting between Fock spaces in terms of the objects t-Berezin transforms, averaging functions, and averaging sequences of μ. We also obtain an asymptotic estimate for the norms of the operators. The results extend and complete a recent work of Z. Hu and X. Lv when both the smallest and the largest Banach–Fock spaces are taken into account.     

Extremal Problems of Approximation Theory in Linear Spaces

We propose an approach that enables one to pose and completely solve main extremal problems in approximation theory in abstract linear spaces. This approach coincides with the traditional one in the case of approximation of sets of functions defined and square integrable with respect to a given -additive measure on manifolds in R ^m, m 1.     

Frechet空间上的一些等距逼近问题

本文主要讨论Fréchet空间上ε-等距线性算子的等距逼近问题, 证明了任意有限维Fréchet空间之间的等距逼近问题都是肯定的; 无穷维Fréchet空间(s)空间上的等距逼近问题也是肯定的.     

Bergman空间上Toeplitz算子的局部化

In this paper we characterize the essential spectra of Toeplitz operators on Bergman spaces by using Douglas‘ localization Theorem and obtain the local decomposition of the essential spectra of Toeplitz operators.     

Toeplitz Operators and Algebras on Dirichlet Spaces

ＬｅｔＤｂｅｔｈｅｕｎｉｔｄｉｓｋｉｎｔｈｅｃｏｍｐｌｅｘｐｌａｎｅＣ,ａｎｄｄＡ（ｚ）＝１πｄｘｄｙｔｈｅｎｏｒｍａｌｉｚｅｄＬｅｂｅｓｇｕｅｍｅａｓｕｒｅｏｎＤ．ＴｈｅＳｏｂｏｌｅｖｓｐａｃｅＬ２,１ｉｓｄｅｆｉｎｅｄｔｏｂｅｔｈｅｃｏｌｅｃｔｉ...     

On Symmetrizable Operators on Hilbert Spaces

This paper, motivated by transport theory, deals with spectral properties of operators G on a complex Hilbert space H such that SG is self-adjoint where S is a nonnegative operator: We give several lower bounds of the spectral radius of G and determine the latter in some cases. We derive the whole spectrum for power compact G by means of Lagrange multiplier theory. We find out spectral connections between G and SG. We give a (spectral) stability estimate for symmetrizable operators in terms of the spectral radius of the perturbation.     

Hilbert空间中广义平衡问题和不动点问题的粘滞逼近法

在Hilbert空间,我们用粘滞逼近法建立了一迭代序列来逼近两个集合的公共点,这两个集合分别是广义平衡问题的解集和渐进非扩张映射的不动点集.我们表明这一迭代序列强收敛到这两个集合的公共点,而且这一公共点还是一变分不等式的解.用这一结果,还研究了三个强收敛问题和优化问题.     

Toeplitz Operators on Arveson and Dirichlet Spaces

We define Toeplitz operators on all Dirichlet spaces on the unit ball of and develop their basic properties. We characterize bounded, compact, and Schatten-class Toeplitz operators with positive symbols in terms of Carleson measures and Berezin transforms. Our results naturally extend those known for weighted Bergman spaces, a special case applies to the Arveson space, and we recover the classical Hardy-space Toeplitz operators in a limiting case; thus we unify the theory of Toeplitz operators on all these spaces. We apply our operators to a characterization of bounded, compact, and Schatten-class weighted composition operators on weighted Bergman spaces of the ball. We lastly investigate some connections between Toeplitz and shift operators. The research of the second author is partially supported by a Fulbright grant.     

Hilbert空间上线性算子的Drazin可逆性

主要研究了Hilbert空间上两个Drazin可逆算子和的Drazin可逆性.同时,对上三角算子矩阵的Drazin可逆性也给出了详细的讨论.     

解析Moerry型空间的性质与Toeplitz算子

在广义权函数下,研究了解析Moerry型空间H_K~2的若干性质.与此同时,还研究了H_K~2上的Toeplitz算子.     

Dirichlet型空间上Toeplitz算子的本性范数

本文研究单位圆盘上Dirichlet型空间非紧Toeplitz算子的本性范数, 它事实上等于到紧Toeplitz算子集的距离. 并且这个距离可由无限多个紧Toeplitz算子来刻画, 这个结果与加权Bergman空间情形的类似.     

Dirichlet空间上Toeplitz算子的一些性质

该文研究了Dirichlet空间D^p~(1< p<∞)上Toeplitz算子的紧性与Fredholm性质, 计算了D^p上Toeplitz算子的Fredholm指标. 还考查了D^p上Hankel算子紧性.